#!/usr/bin/perl

my @t = ("A\x{300}B",       # U+0300 GRAVE ACCENT
         "AA",
         "A\x{41}\x{300}",  # U+0041 LATIN CAPITAL LETTER A
         "\x{55}\x{308}O",  # U+0308 COMBINING DIAERESIS 
         "\x{dc}U"          # U+00DC capital U with DIAERESIS
);

binmode(STDOUT, ':utf8');

for (@t) {
  print "MATCH: $_\n" if /\p{Lu}{2}/;
}